Ventilating apparatus



July 18, 1950 G. H. DINGMAN VENTILATING APPARATUS Filed Sept. 13, 1946Fig.2.

INVENTORu GLEN H DINGMAN ATTORNEY.

Patented July 18, 1950 VENTILATING APPARATUS Glen H. Dingman, Sidney, N.Y., assignor to Bendix Aviation Corporation, New York, N. Y., acorporation of Delaware Application September 13, 1946, Serial No.696,905

Claims.

This invention relates to ventilation, and particularly to theventilation of machinery. It finds valuable use in the structure ofmagneto casings, and in the casings of exothermic machinery or ofmachinery that is liable to burn or to be enveloped in flameoccasionally, and in such use serves a valuable protective function.

It is an object of the invention to construct a ventilator for machinerycasings, adapted to a wide variety of other and similar employments,that is capable of ventilating the machinery and of releasing excessheat while restraining flame from passing through the ventilator.

Another object is to construct a ventilator capable of performing theindicated functions and of being assembled from simple parts that can beeasily dismantled for cleaning.

The objects of the invention are accomplished, generally speaking, byconstructing in the wall of the space to be ventilated a plurality ofinterconnected chambers adapted to reduce the velocity of hot gasespassing therethrough without reducing their rate of discharge, having anadditional flame arresting function, and constituting a pneumatic maze.A preferred structure for accomplishing these objects is described inthe specification and illustrated in the drawing as a ventilator for amagneto casing, but it is to be understood that the particular useconstitutes no limitation.

The above and further objects and novel features of the invention willmore fully appear from the following detailed description when the sameis read in connection with the accompanying drawings. ever, that thedrawings are for purposes of illustration only and are not intended as adefinition of the limits of the invention, reference for this latterpurpose being had primarily to the appended claims.

In the drawings, wherein like reference char acters refer to like partsthroughout the several views,

Fi 1 is a vertical elevation of a casing memher having a centrallylocated ventilator of the type described;

Fig. 2 is a vertical section on the line 2-2 of Fig. 1; and

Fig. 3 is an exploded view of the parts of the ventilator, in endelevation.

In the drawing the numeral iii indicates a section of a magneto casingwall having a slit H and a portion I2 above the slit, ofiset to providean orifice E3 of considerable length and gas flow capacity. This orificefaces downwardly as It is to be expressly understood, howshown in thedrawing but could be faced in any other direction to serve the needs ofa particular construction, as for instance being faced rearwardly on amoving body to provide suction. Gas may pass to the space within thebulge i2 through the slot E3, or it may be discharged therefrom. In eachinstance its motion will be mainly parallel to the casing wall as itleaves the slot.

A double chamber and pneumatic maze is made by attaching over the hollowof the bulge a chamher having an inner plate i i and an outer plate l5,which are spaced apart to form a chamber It by offset edge flanges ll,ll. These plates are identical and may be conveniently made by astamping process. In each of them is a slot, indicated by numerals l8,it, which are arranged in offset relation to each other and to the sloti3, providing a pneumatic maze that must be traversed by the gases, andorifices receiving and discharging gases in different directions.

Thus, in Fig. 2 gas travelling from left to right enters the slot [8horizontally, suffers a degree change in direction and travels theheight of chamber I6, changes direction 90 degrees to pass through slotI 8' and again 90 degrees to travel the depth of chamber E9 betweenbulge i2 and plate 14, being discharged at an angle to its direction ofentry. This different angle of entry and discharge tends to overcome thefault that arises when inlet and outlet are identically directed and aremade ineffective by equal pressure in the one direction.

The chamber I6 is of such size that the velocity of the gases that enterit from orifice i8 is reduced. The chamber i9 is of even greater size.This system of chambers is calculated to reduce the velocity of hotgases proceeding through the ventilator so that the temperature of anexplosion flame will be reduced to a relatively harmless degree insidethe ventilator.

In order to further provide against the passage of flame the flanges!li"l hold clamped between them a wire screen 24]. This screen dividesthe chamber l6 and acts as a flame barrier. It is preferably made ofphosphor bronze wire cloth of about .0045 in. wire diameter having about30% open area. This may be accomplished by a weave of about x 100 mesh,and openings of about .0055 in. Total thickness of the screen is about.009 in. plus or minus .003 in.

The chamber I5 is assembled as a unit and attached over the bulge l2 byrivets 2! Or by more easily removable bolts. The bolts are preferred incases where the passages of the screen act as a filter and becomeclogged, being thus easily removed for cleaning. Screw threaded studsmay be mounted on and project from the casing, upon which the chamber 16is attached by nuts.

The advantages of the invention are material. The structure is simple,cheap to make, and easy to assemble or dismantle. It acts both as aventilator and as a fire trap. The arrangement and size of the orifices,the directional changes in the maze, the screen and its construction,and the chamber sizes all contribute to the eflicient performance of theunit.

Although only a single embodiment of the present invention is hereinillustrated and described, it is to be expressly understood that theinvention is not limited thereto. Various changes may be made in thedesign and arrangement of the parts and in the materials used withoutdeparting from the spirit and scope of the invention, as will now beapparent to persons skilled in the art. For a definition of the limitsof the invention, reference is had primarily to the appended claims.

What is claimed is:

1. Ventilating apparatus for a casing or the like comprising a Wallhaving a bulge forming a recess in one face thereof and a slot at oneedge of said recess whereby the latter is open to the other face of thewall, a chamber assembly comprising a pair of plates havin peripheralflanges in face-to-face relation and center portions shaped to form afirst chamber between the plates, and means for securing said assemblyto said wall across said recess and forming the latter into a secondchamber, the inner plate of said pair constituting a wall between saidchambers and having a slot therein connecting said chambers adjacent theedges thereof opposite said first-named slot and the other of saidplates 4 having a slot therein extending across the other edge of saidfirst chamber.

2. Ventilating apparatus as defined in claim 1 wherein the bulge formingthe outer wall of said second chamber is an offset integral part of thewall of the casing.

3. Ventilating apparatus as defined in claim 1 wherein the centerportions of said plates are oppositely bulged to form said firstchamber.

4. Ventilating apparatus as defined in claim 3 wherein said plates aresubstantially identical stampings assembled in opposed face-to-facerelation with the slots therein at opposite edges of the chamber formedtherebetween.

5. Ventilating apparatus as defined in claim 3 wherein the chamberassembly comprises a metallic screen extending across said first chamberand having the periphery thereof securely clamped between the peripheralflanges of said plates.

GLEN H. DINGMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,385,995 Hellmund Aug. 2, 1 9211,420,411 Currie June 20, 1922 1,723,412 De Waters Aug. 6, 19291,730,237 Patten Oct. 1, 1929 1,960,259 Wyman May 29, 1934 2,150,859Gibson et a1. Mar. 14, 1939 2,151,180 Anschicks Mar. 21, 1939 2,279,961Whittaker Apr. 14, 1942

